Presidential campaigns put their potential vice-presidential picks through a gruelling vetting process before they can join the ticket - one past participant likens it to "a colonoscopy".
Have you ever paid for sex?
Have you ever paid for an abortion?
Have you ever had a homosexual encounter?
Those are just some of the questions VP hopefuls might face.
The vetters pore over a contender’s tax returns and medical history.
They may log on to his or her private social media accounts. They even scour the social media posts of his or her children and grandchildren.
Evan Bayh, a finalist to become Barack Obama’s running mate in 2008, remembers the procedure took nearly three months and was "like having a colonoscopy performed with a telescope".
"There was a whole team assigned to me: an accountant, a lawyer, a physician," the former Indiana senator and governor told the BBC.
The head of the vetting team phoned one day to ask Bayh about a false internet rumour that he had once received psychiatric treatment.
"And I said, ‘No, it's not true. But if you guys don't hurry up and make a decision, it might be true.'"
